In an effort to enhance the level of comfort for the seat occupant, it is possible for the seat to be designed in such a way as to provide what might be called a heating effect or a vibration effect. That consideration may be particularly important for example in relation to a vehicle seat in which the seat occupant's comfort can be a matter of paramount importance. A commonly used cushion for a seat is shown in FIG. 1, which is simply a soft pad for reclining the user's lumbar region and does not have any other functions. FIG. 2 illustrates another prior art cushion for a seat, which does not have any functions relating to lumbar support, massage or magnetic stimulation, but does provide for a heating effect. Furthermore, such a cushion has no safety means for the heating device so that accidents may happen once the user forgets to turn off the power switch after use. FIGS. 3 and 4 show a third commonly used cushion, which utilizes an external control box D to control an adjustable air pouch A to adapt to the user's lumbar region, a heating device B to produce a heating effect, and a vibration device C to provide a massaging effect. Nevertheless, such a cushion still has the following drawbacks:
1. All functions are controlled by the external control box which is complicated in operation and the cushion may lose all functions once the external control box does not work properly.
2. As an external control box is required for the control of the cushion, the manufacturing cost will be increased significantly making it difficult to be widely used.
3. Since all functions of the cushion are controlled by the external control box, the circuit and structure of the cushion will be complicated and therefore will be more prone to failure.
4. Due to the fact that the cushion is controlled by an external control box, it is necessary to arrange a space to accommodate the external control box thus making it inconvenient to use.
5. The vibration device is mounted on the upper half of the back portion of the cushion, so only the user's back can be massaged.
6. Once the user forgets to turn off the power switch after use, the vibration motor and the heating device may become overheated and burn out thereby wasting energy and potentially causing accidents.
7. As the air pouch is fitted in the lower portion of the back rest of the cushion, the heating device only can be mounted in the upper portion of the back rest of the cushion and cannot be used to provide the right heating effect for the lumbar portion of the user.
8. Such a cushion cannot be used with alternating current, so it is only suited to be used with vehicle seats and cannot be used with any other seats.
9. Such a cushion is so large in size that it is inconvenient for the user to carry or otherwise transport it.
Therefore, it is an object of the present invention to provide a multi-function cushion which can obviate and mitigate the above-mentioned drawbacks.